---
title: "GB/T 845 Cross Flat-Head Knurled Self-Tapping Screws Specification"
description: "GB/T 845 Cross Flat-Head Knurled Self-Tapping Screws: full dimensional table with tolerances. DIN, ISO and ASME equivalents listed side by side."
url: https://engineeringhardware.com/guide/standard/gb-t-845-cad-svg-045-tapping/
source: Engineering Hardware & Fasteners
---

# GB/T 845 Cross Flat-Head Knurled Self-Tapping Screws Specification

Screws · GB/T 845 / DIN 7981 / GB/T 5267.1

Dimensional table, tolerance classes and the DIN / ISO / ASME parts that supersede or match this standard.

GB/T 845 specifies the dimensions and tolerances for cross flat-head knurled self-tapping screws. The full dimensional table is reproduced below, followed by the DIN, ISO and ASME parts that match or supersede it.

- **Standard:** GB/T 845
- **Product:** Cross Flat-Head Knurled Self-Tapping Screws
- **Governing standards:** GB/T 845 / DIN 7981 / GB/T 5267.1

Equivalence between national standards is dimensional, not always metallurgical. Check the property class separately when substituting.

![GB/T 845 Cross Flat-Head Knurled Self-Tapping Screws Specification reference image](https://engineeringhardware.com/wp-content/uploads/2026/09/Cross-Flat-Head-Knurled-Self-Tapping-Screws.webp)

For cross flat-head knurled self-tapping screws, GB/T 845 is the governing document for the dimensions listed below. Mechanical and performance requirements for this part family are set by its own standards, not by the bolt and screw property-class documents.

## GB/T 845 — Scope

GB/T 845 is "Cross-recessed pan head tapping screws". GB/T 845 is the Chinese national adoption of the same document.

Material, property class, surface finish and packaging are governed by separate documents — ISO 898-1 and ISO 898-2 for mechanical property classes, ISO 4042 for electroplated finishes.

## Tolerance & Product Grades

GB/T 845 does not divide cross flat-head knurled self-tapping screws into product grades. Tolerances are given as limits on the individual dimensions in the table.

Where a general-tolerance class is cited on the drawing instead, it applies to the dimensions not otherwise toleranced.

## Dimensions Specified by GB/T 845

| Head form | Under-head feature | Material | Finish options | Substrate |
| --- | --- | --- | --- | --- |
| cross-recess flat head | under-head knurling | carbon steel | zinc plating | wood |
| cross-recess flat head | under-head knurling | carbon steel | colour zinc plating | plastic |
| cross-recess flat head | under-head knurling | carbon steel | black oxide | thin plate |

## Equivalent Standards

Where direct equivalents exist (ISO ↔ DIN, ISO ↔ ASME), they are listed on the parent Cross Flat-Head Knurled Self-Tapping Screws page.

Always confirm against the dimensions on this page, since some "equivalent" standards differ in tolerances and head geometry.

## When to Specify GB/T 845

Choose GB/T 845 for international engineering work and OEM supply where ISO standards are the contractual reference. It is the default modern specification for cross flat-head knurled self-tapping screws.

Custom manufacturing · Made to drawing

## Need a screw to this standard in a non-standard size?

Parts built to GB T 845 are already in the catalog, so a special is usually a variation on existing tooling rather than a new design — which is what keeps the cost down. Made by cold heading or warm forging.

Minimum order from 2,000 pieces; samples within 7 days of drawing approval.

[Custom screw manufacturing](https://engineeringhardware.com/custom/screws/)[Send a drawing](https://engineeringhardware.com/custom/screws/#rfq)

## Technical Drawing

Dimensioned line drawing of cross-recess flat head Cross Flat-Head Knurled Self-Tapping Screws to GB/T 845 / DIN 7981 / GB/T 5267.1. Side view and top view, drawn to the dimensions in the table below and redrawn for any size selected.

- **Under-head feature:** under-head knurling
- **Material:** carbon steel
- **Finish options:** zinc plating
- **Substrate:** wood

## Dimensions & Specifications (GB/T 845 / DIN 7981 / GB/T 5267.1)

| Head form | Under-head feature | Material | Finish options | Substrate |
| --- | --- | --- | --- | --- |
| cross-recess flat head | under-head knurling | carbon steel | zinc plating | wood |
| cross-recess flat head | under-head knurling | carbon steel | colour zinc plating | plastic |
| cross-recess flat head | under-head knurling | carbon steel | black oxide | thin plate |

Product catalog

## Related Knurled Self-Tapping Screws products

[![Thickened Screws Cross Pan Head Self-Tapping Screws Screws with Low Price](https://img.engineeringhardware.com/Thickened-Screws-Cross-Pan-Head-Self-Tapping-Screws-Screws-with-Low-Price.webp)](https://engineeringhardware.com/product/thickened-screws-cross-pan-head-self-tapping-screws-screws-with-low-price/)

Self-Tapping & Thread-Forming Screws

### [Thickened Screws Cross Pan Head Self-Tapping Screws Screws with Low Price](https://engineeringhardware.com/product/thickened-screws-cross-pan-head-self-tapping-screws-screws-with-low-price/)

Hexagon Head · GB

**US$0.0816 – 0.084**MOQ 50,000 pieces

[![304 316 Ss Truss Pan Phillips Umbrella Mushroom Head Self Tapping Screw](https://img.engineeringhardware.com/304-316-Ss-Truss-Pan-Phillips-Umbrella-Mushroom-Head-Self-Tapping-Screw.webp)](https://engineeringhardware.com/product/304-316-ss-truss-pan-phillips-umbrella-mushroom-head-self-tapping-screw/)

Self-Tapping & Thread-Forming Screws

### [304 316 Ss Truss Pan Phillips Umbrella Mushroom Head Self Tapping Screw](https://engineeringhardware.com/product/304-316-ss-truss-pan-phillips-umbrella-mushroom-head-self-tapping-screw/)

DIN, ASTM, GOST, GB, JIS, ANSI, BS · Metal

**US$0.008 – 0.0084**MOQ 50,000 pieces

[![Stainless Steel Self Tapping Screw with Thread Cutting for Interior Carpentry](https://img.engineeringhardware.com/Stainless-Steel-Self-Tapping-Screw-with-Thread-Cutting-for-Interior-Carpentry.webp)](https://engineeringhardware.com/product/stainless-steel-self-tapping-screw-with-thread-cutting-for-interior-carpentry/)

Self-Tapping & Thread-Forming Screws

### [Stainless Steel Self Tapping Screw with Thread Cutting for Interior Carpentry](https://engineeringhardware.com/product/stainless-steel-self-tapping-screw-with-thread-cutting-for-interior-carpentry/)

Self Tapping Screw · DIN, ISO

**US$0.012 – 0.24**MOQ 1,000 pieces

[![China Hardware Wholesale Self-Tapping Black Drywall Screws](https://img.engineeringhardware.com/China-Hardware-Wholesale-Self-Tapping-Black-Drywall-Screws.webp)](https://engineeringhardware.com/product/china-hardware-wholesale-self-tapping-black-drywall-screws/)

Self-Tapping & Thread-Forming Screws

### [China Hardware Wholesale Self-Tapping Black Drywall Screws](https://engineeringhardware.com/product/china-hardware-wholesale-self-tapping-black-drywall-screws/)

Round Head · GB

**US$1,116 – 1,140**MOQ 1 ton

[![Ss 304 316 Stainless Steel Long Shank Forged Hook Eye Pigtail Tapping Screw with Drawings](https://img.engineeringhardware.com/Ss-304-316-Stainless-Steel-Long-Shank-Forged-Hook-Eye-Pigtail-Tapping-Screw-with-Drawings.webp)](https://engineeringhardware.com/product/ss-304-316-stainless-steel-long-shank-forged-hook-eye-pigtail-tapping-screw-with/)

Self-Tapping & Thread-Forming Screws

### [Ss 304 316 Stainless Steel Long Shank Forged Hook Eye Pigtail Tapping Screw with Drawings](https://engineeringhardware.com/product/ss-304-316-stainless-steel-long-shank-forged-hook-eye-pigtail-tapping-screw-with/)

Bending Type · DIN, ANSI, GB, JIS, BSW, GOST, Per Customers'desire

**US$0.072 – 0.31**MOQ 100,000 pieces

[![Yellow Zinc Torx Drive Stainless Steel Self Tapping Wood Screw Double Countersunk Flat Head Hex Head for Chipboard](https://img.engineeringhardware.com/Yellow-Zinc-Torx-Drive-Stainless-Steel-Self-Tapping-Wood-Screw-Double-Countersunk-Flat-Head-Hex-Head-for-Chipboard.webp)](https://engineeringhardware.com/product/yellow-zinc-torx-drive-stainless-steel-self-tapping-wood-screw-double-countersunk/)

Self-Tapping & Thread-Forming Screws

### [Yellow Zinc Torx Drive Stainless Steel Self Tapping Wood Screw Double Countersunk Flat Head Hex Head for Chipboard](https://engineeringhardware.com/product/yellow-zinc-torx-drive-stainless-steel-self-tapping-wood-screw-double-countersunk/)

DIN, ANSI, GB, JIS, BSW, GOST · Low Carbon Steel

**US$0.012**MOQ 10,000 pieces

[View all Self-Tapping & Thread-Forming Screws →](https://engineeringhardware.com/fastener-products/screws/self-tapping-thread-forming-screws/) [Full product catalog](https://engineeringhardware.com/products/)

## Materials & Grades

Select a material class to see the grades we supply it in. Each designation is listed with its ISO/EN, AISI/SAE, JIS and GB equivalents.

Stainless Steel38 Carbon Steel66 Alloy Steel41 Bearing Steel5 Spring Steel25 Aluminum and Aluminum Alloys21 Brass17 Bronze11 Copper8 Titanium and Titanium Alloys18 Nickel and Nickel Alloys22 Iron-Nickel and High-Temperature Alloys10 Tool Steel and Specialty Hardened Steel9 Structural and Construction Steel9

### Stainless Steel

#### Austenitic Stainless Steel

- A1 AISI 303 · SAE 303 · SUS303 · EN 1.4305 · X8CrNiS18-9
- A2 AISI 304 · SAE 304 · SUS304 · EN 1.4301 · X5CrNi18-10 · 06Cr19Ni10
- 304L AISI 304L · SUS304L · EN 1.4307 · X2CrNi18-9 · 022Cr19Ni10
- 302 AISI 302 · SUS302 · EN 1.4310
- 305 AISI 305 · SUS305 · EN 1.4303
- A4 AISI 316 · SAE 316 · SUS316 · EN 1.4401 · X5CrNiMo17-12-2 · 06Cr17Ni12Mo2
- 316L AISI 316L · SUS316L · EN 1.4404 · X2CrNiMo17-12-2 · 022Cr17Ni12Mo2
- 321 AISI 321 · SUS321 · EN 1.4541 · X6CrNiTi18-10
- 310 / 310S AISI 310 · AISI 310S · SUS310S · EN 1.4845
- 302HQ AISI 302HQ
- A3
- A5
- 347 AISI 347 · SUS347 · EN 1.4550 · X6CrNiNb18-10
- 309 / 309S AISI 309 · AISI 309S · SUS309S

#### Martensitic Stainless Steel

- AISI 410 SUS410 · EN 1.4006 · X12Cr13 · 12Cr13
- AISI 420 SUS420J1 · SUS420J2 · EN 1.4021 · EN 1.4028 · 20Cr13 · 30Cr13
- AISI 431 SUS431 · EN 1.4057 · X17CrNi16-2
- C1
- C3
- C4
- AISI 440A
- AISI 440B
- AISI 440C SUS440C · EN 1.4125

#### Ferritic Stainless Steel

- AISI 430 SUS430 · EN 1.4016 · X6Cr17 · 10Cr17
- F1
- AISI 434
- AISI 444

#### Precipitation-Hardening Stainless Steel

- 17-4 PH AISI 630 · UNS S17400 · SUS630 · EN 1.4542 · X5CrNiCuNb16-4
- 15-5 PH UNS S15500
- 17-7 PH UNS S17700

#### Duplex and Super Duplex Stainless Steel

- Duplex 2205 UNS S31803 · UNS S32205 · EN 1.4462
- Super Duplex 2507 UNS S32750 · EN 1.4410
- D2
- D4
- D6
- D8
- Lean Duplex 2101 UNS S32101
- Super Duplex S32760 UNS S32760 · EN 1.4501

### Carbon Steel

#### Low-Carbon Steel

- SAE 1006
- SAE 1008
- SAE 1010
- SAE 1018
- SAE 1020
- Q195
- Q235
- SAE 1012
- SAE 1015
- Q215
- ML08
- ML08Al
- ML10
- ML15
- ML20
- SWRCH6A
- SWRCH8A
- SWRCH10A
- SWRCH12A
- SWRCH15A
- SWRCH18A

#### Medium-Carbon Steel

- SAE 1035
- SAE 1045
- S45C
- C45
- SAE 1030
- SAE 1040
- SAE 1050
- 30
- 35
- 40
- 45
- 50
- S35C
- S40C
- S50C
- C35
- C40

#### High-Carbon Steel

- SAE 1060
- SAE 1070
- 65Mn
- SAE 1065
- SAE 1075
- SAE 1080
- SAE 1085
- SAE 1090
- SAE 1095
- 60
- 65
- 70
- 75
- 80
- 85

#### Cold-Heading Steel

- SWRCH22A
- 10B21
- SWRCH22K
- SWRCH25K
- SWRCH30K
- SWRCH35K
- SWRCH40K
- ML20Mn
- ML25
- ML30
- ML35
- ML40
- 15B25

### Alloy Steel

#### Chromium Steel

- 40Cr
- 45Cr
- AISI 5140
- SAE 5140
- AISI 5120
- SAE 5120
- SCr420
- SCr440

#### Chromium-Molybdenum Steel

- 35CrMo
- 42CrMo
- AISI 4140
- SCM435
- SCM440
- 42CrMo4
- 30CrMo
- AISI 4130
- SAE 4130
- SAE 4140
- AISI 4142
- AISI 4145
- SCM415
- SCM420
- SCM445
- EN 1.7220
- EN 1.7225
- 25CrMo4
- 34CrMo4

#### Nickel-Chromium-Molybdenum Steel

- AISI 4340
- SAE 4340
- 40CrNiMo
- SNCM439
- EN 1.6511
- 36CrNiMo4

#### Boron Alloy Steel

- 10B22
- 10B21
- 15B21
- 15B25
- 20MnTiB
- 20Mn2B
- 35VB
- 40MnB

### Bearing Steel

#### Bearing Steel

- GCr15
- AISI 52100 SAE 52100 · UNS G52986
- SUJ2
- 100Cr6 EN 1.3505
- GCr15SiMn

### Spring Steel

#### Carbon Spring Steel

- SAE 1065
- SAE 1070
- SAE 1075
- SAE 1080
- SAE 1095
- 65
- 70
- 75
- 80
- 65Mn

#### Silicon-Manganese Spring Steel

- 60Si2Mn
- 60Si2MnA
- SUP6
- SUP7

#### Chromium-Vanadium Spring Steel

- 50CrVA
- SAE 6150
- AISI 6150
- SUP10

#### Stainless Spring Steel

- AISI 301
- SUS301
- EN 1.4310
- AISI 302
- AISI 304
- AISI 316
- 17-7 PH

### Aluminum and Aluminum Alloys

#### Commercially Pure Aluminum

- 1050
- 1060
- 1070
- 1100

#### 2xxx Series Aluminum

- 2024
- 2011
- 2014
- 2017

#### 5xxx Series Aluminum

- 5052
- 5083
- 5754

#### 6xxx Series Aluminum

- 6061
- 6061-T6
- 6063
- 6082
- 6082-T6

#### 7xxx Series Aluminum

- 7075
- 7075-T6
- 7005
- 7050
- 7075-T73

### Brass

#### Free-Cutting Brass

- C36000
- H62
- HPb59-1
- C3601
- C3602
- C3604
- CuZn36Pb3
- CuZn39Pb3
- EN CW614N
- EN CW617N
- H65

#### Lead-Free Brass

- C69300
- C27450
- CW510L
- CW511L

#### Naval Brass

- C46400
- CuZn39Sn1

### Bronze

#### Silicon Bronze

- C65500
- C65100
- C65600

#### Phosphor Bronze

- C51000
- C52100
- CuSn6
- CuSn8

#### Aluminum Bronze

- C95400
- C95500
- C63000
- CuAl10Ni5Fe4

### Copper

#### Copper

- C11000
- T2
- C10100
- C10200
- C12200
- T1
- TU1
- TU2

### Titanium and Titanium Alloys

#### Commercially Pure Titanium

- Grade 2
- Grade 1
- Grade 3
- Grade 4
- TA1
- TA2
- TA3

#### Alpha-Beta Titanium Alloys

- Grade 5
- Ti-6Al-4V
- TC4
- UNS R56400

#### Low-Interstitial Grade

- Grade 23
- Ti-6Al-4V ELI
- UNS R56407

#### Other Titanium Fastener Alloys

- Ti-6Al-6V-2Sn
- Ti-6Al-2Sn-4Zr-2Mo
- Beta-C titanium
- Ti-10V-2Fe-3Al

### Nickel and Nickel Alloys

#### Commercially Pure Nickel

- Nickel 200
- UNS N02200
- Nickel 201
- UNS N02201

#### Inconel Alloys

- Inconel 625 UNS N06625
- Inconel 718 UNS N07718
- Inconel 600 UNS N06600
- Inconel 601 UNS N06601
- Inconel 686 UNS N06686
- Inconel X-750 UNS N07750

#### Monel Alloys

- Monel 400 UNS N04400
- Monel K-500 UNS N05500

#### Hastelloy Alloys

- Hastelloy C-276 UNS N10276
- Hastelloy C-22 UNS N06022
- Hastelloy B-2 UNS N10665
- Hastelloy B-3 UNS N10675
- Hastelloy X UNS N06002

#### Other Nickel Alloys

- Alloy 20 UNS N08020
- Alloy 625
- Alloy 718
- Alloy 825 UNS N08825
- Alloy 925 UNS N09925

### Iron-Nickel and High-Temperature Alloys

#### A286

- A-286
- UNS S66286
- EN 1.4980

#### Invar

- Invar 36
- Alloy 36
- UNS K93600
- FeNi36

#### Alloy 42

- Alloy 42
- UNS K94100
- FeNi42

### Tool Steel and Specialty Hardened Steel

#### Tool Steel and Specialty Hardened Steel

- AISI D2
- AISI H13
- SKD11
- Cr12MoV
- AISI O1
- AISI A2
- AISI S7
- SKD61
- 9CrSi

### Structural and Construction Steel

#### Structural and Construction Steel

- ASTM A36
- Q235B
- Q355B
- S355JR
- Q235C
- Q355C
- S235JR
- S275JR
- S355J2

## Applications & Industries

The sectors that buy Cross Flat-Head Knurled Self-Tapping Screws to GB/T 845 / DIN 7981 / GB/T 5267.1, and the duty each one buys them for.

### Industries that specify Cross Flat-Head Knurled Self-Tapping Screws

- **Plastic assemblies:** Flat head seats without cracking a thin moulding.
- **Sheet-metal work:** Extra friction against vibration without a thread locker.
- **General fabrication:** Zinc, colour zinc and black oxide for the visible finish.
- **Furniture manufacture:** Under-head knurling bites the surface and resists backing out.
- **Construction & fit-out:** Fixing board, batten, framing and trim into timber and light-gauge steel.
- **Sheet-metal & HVAC:** Ducting, enclosures, trunking and cladding assembled without tapped holes.

### Typical applications

- choosing the finish to suit the visible face
- selecting for wood, plastic or thin plate
- keeping installation torque within what the parent material takes
- letting the knurl bite the mating surface as the head seats
- fixing where there is no access to add a nut behind the panel
- high-volume driving with a bit and a clutch-set driver

### Service conditions to specify against

- **Marine and coastal:** Available in A4 (316) stainless for chloride exposure — coastal structures, pool halls, water treatment and deck hardware, where A2 will eventually pit.
- **Pilot hole:** Selection is really a hole-size decision: too small and the screw snaps or splits the material, too large and it strips. The size is stated per row.

### Where to use something else

- Do not use a knurled head where the surface must stay unmarked; the knurl works by scoring it.
- Not for a joint that will be dismantled and reassembled repeatedly in the same hole — use an insert or a rivet nut instead.

[Full application guide: where Cross Flat-Head Knurled Self-Tapping Screws are used, how to specify them, and the cases they are wrong for](https://engineeringhardware.com/applications/cross-flat-head-knurled-self-tapping-screws/)

Inside the plant

## Manufactured in our own plant

This part is cold-formed, threaded, heat-treated and finished in-house. The stages below are where its class and finish are actually decided.

1. ![Wire rod feeding into a cold heading machine](https://engineeringhardware.com/wp-content/uploads/2026/08/09-wire-rod-feed-cold-heading-machine.webp) 01 **Cold heading** Wire rod is drawn to size and cold-formed into blanks. Forming rather than cutting keeps the grain flow continuous around the head, which is where a bolt is most likely to fail. Head dimensions and under-head radius checked at set-up and per shift.
2. ![Thread rolling machine producing bolt threads](https://engineeringhardware.com/wp-content/uploads/2026/08/03-thread-rolling-machine-bolt-production.webp) 02 **Thread rolling** Threads are rolled between hardened dies rather than cut. Rolled threads are stronger in fatigue than cut threads and hold pitch and flank angle far more consistently across a batch. Go / no-go ring gauges to ISO 965 tolerance class 6g.
3. ![Baskets of bolts staged for heat treatment](https://engineeringhardware.com/wp-content/uploads/2026/08/05-heat-treatment-baskets-black-bolts.webp) 03 **Heat treatment** Quench-and-temper brings carbon and alloy steel to the property class ordered — 8.8, 10.9 or 12.9 — with the furnace charge tracked so a finished lot can be traced back to it. Core hardness and tensile tested per lot to ISO 898-1.
4. ![Zinc plated bolts in a treatment basket](https://engineeringhardware.com/wp-content/uploads/2026/08/23-zinc-plated-bolts-treatment-basket.webp) 04 **Surface treatment** Zinc, zinc-nickel, hot-dip galvanizing, black oxide, phosphate and Dacromet, selected against the service environment rather than against the price list. Coating thickness and neutral salt spray hours to ISO 9227.

## Frequently Asked Questions

### Does GB/T 845 specify the mechanical strength?

No. GB/T 845 controls only the geometry of cross flat-head knurled self-tapping screws. The mechanical strength is set by ISO 898-1 (bolts, screws and studs) or ISO 898-2 (nuts), and the finish by separate documents.

### Can I substitute GB/T 845 for the corresponding DIN standard on a drawing?

On modern drawings the ISO standard is the master reference; the older DIN equivalent is a cross-reference. For most dimensional purposes the parts are interchangeable, but check tolerance grades and the head height — these are the most common points of divergence.

### Which edition of GB/T 845 does this table follow?

The table reproduces the dimensions we supply cross flat-head knurled self-tapping screws to. We do not publish an edition year against it, so where the edition is contractually significant, cite the edition you require on the enquiry and we will confirm it against the table before quoting.

### What is GB/T 845?

GB/T 845 is "Cross-recessed pan head tapping screws". GB/T 845 is the Chinese national adoption of the same document.

### How do I request a quotation?

Use the technical drawing on this page to pick the exact configuration, then submit it with the quote form. We respond within one business day.

## Related Pages

[View the full Cross Flat-Head Knurled Self-Tapping Screws page](https://engineeringhardware.com/fastener/cross-flat-head-knurled-self-tapping-screws/)

### More Cross Flat-Head Knurled Self-Tapping Screws Guides